Wednesday, March 7, 2012

Weather and the Tirreno-Adriatico Prologue

Earlier today, Marco Pinotti tweeted, "Last 7 team to start are all in the 3rd part of final classification. Wind was a factor today." Following Monday's post I'm interested in the individual data that time trials generate. Can we see points of interest in graphing results?

A scatterplot of finishing order by starting position shows a noticeable upward trend (the green line is the least-squares regression line). Nobody who started in the last nine finished in the top ten, and BMC, a powerful team time trialing team, finished poorly and cited the weather. What does that tell us?

Compare that chart to a windchart from that day, below. Shortly after the time trial begins, the winds pick up, and halfway through the time trial, they switch from a crosswind to a headwind (most of the time trial was northbound).

NB: Starting order of a time trial is not without bias. Controlling for teams' innate difference in ability, and isolating the effect of the wind, would take a different effort.